Currently, many men who are told that they have low-risk prostate cancers are opting for active surveillance, rather than undergoing surgery or radiation treatment. Active surveillance entails monitoring the cancer closely with prostate-specific antigen (PSA) tests, digital rectal exams, and ultrasounds at regular intervals to determine growth status of the tumor. However, according to a new UCLA study, the selection of men for active surveillance should not be based on the widely used conventional biopsy; rather, it should be made with a new, image-guided targeted prostate biopsy. The study was published on May 19 in the Journal of Urology.
The authors note that, at present, almost 400 men are enrolled in the UCLA Active Surveillance program, which is the largest in Southern California. The new image-guided targeted prostate biopsy method was pioneered by a multi-disciplinary UCLA team; it is now a routine part of the UCLA active surveillance program. The team found that conventional “blind” biopsy failed to reveal the true extent of presumed low-risk prostate cancers; when targeted biopsy was used, more than a third of these men had more aggressive cancers than originally thought. Their aggressive cancers were not detected by conventional blind biopsy using ultrasound alone; these men were referred to UCLA’s active surveillance program thinking that they were at no immediate risk.
Since 2009, the targeted biopsy method has been under evaluation at UCLA. It is performed by combining magnetic resonance imaging (MRI) with real-time ultrasound; the method is known as fusion biopsy; it is conducted in a device known as the Artemis. Previous UCLA research demonstrated the value of the new procedure in finding cancers in men with rising PSA who had negative conventional biopsies. This investigators note that their study is the first to show the value of using the procedure early in the selection process for men interested in active surveillance.
“These findings are important as active surveillance is a growing trend in this country,” noted study senior author Dr. Leonard Marks, a professor of urology and director of the UCLA Active Surveillance Program. He added, “It’s an excellent option for many men thought to have slow-growing cancers. But we show here that some men thought to be candidates for active surveillance based on conventional biopsies really are not good candidates.”
For the study, the investigators identified 113 men enrolled in the UCLA active surveillance program who met the criteria for having low-risk cancers based on conventional biopsies. They underwent an MRI to image the prostate and any lesions. That information was then fed into the Artemis device, which fused the MRI pictures with real-time, three-dimensional ultrasound; thus, allowing the urologist to visualize and target lesions during the biopsy.
Dr. Marks explained, “Prostate cancer is difficult to image because of the limited contrast between normal and malignant tissues within the prostate. With the Artemis, we have a virtual map of the suspicious areas placed directly onto the ultrasound image during the biopsy. When you can see a lesion, you’ve got a major advantage of knowing what’s really going on in the prostate.”
Among the 113 study participants, 41 men (36%) were found to have more aggressive cancer than initially suspected; thus, they were not good candidates for active surveillance. Dr. Marks explained that their findings should result in a reevaluation of the criteria for active surveillance. He said, “We are hesitant now to enroll men in active surveillance until they undergo targeted biopsy. Fusion biopsy will tell us with much greater accuracy than conventional biopsy whether or not they have aggressive disease.”
Seventy-year-old Michael Lewis, a Channel Islands Harbor resident, had a slightly elevated PSA; however, he was told after a conventional biopsy that he had no cancer. Six months later, his PSA had soared 50% and he underwent another biopsy; this biopsy also failed to detect a malignancy. A third biopsy found a tiny amount of cancer, which qualified him for active surveillance at UCLA. He was enrolled in the study and underwent a targeted biopsy six months after the previous biopsy. This biopsy revealed more cancer in Mr. Lewis’ prostate than originally suspected. Thus, he actually had an aggressive tumor.
“It was a shock. No one wants to hear they have cancer,” said Mr. Lewis, who recently completed stereotactic body radiation therapy at UCLA. He added, “With the targeted biopsy system, we were able to find my cancer early. It might have been missed otherwise––it actually was missed. Before I came to UCLA, I was told I didn’t even have cancer. I could have been dead––simple as that. Frankly, I owe my life to UCLA.” Dr. Marks noted that Mr. Lewis’ prognosis is good, because the cancer was detected early. Had he continued to receive conventional biopsies, the cancer may have spread before it was detected.
The authors wrote: “For men initially diagnosed with low-risk prostate cancer, MRI-ultrasound confirmatory biopsy including targeting of suspicious lesions seen on MRI results in frequent detection of tumors, These data suggest that for men enrolling in active surveillance, the criteria need be reevaluated to account for the risk inflation seen with targeted prostate biopsy.” Dr. Marks noted that for men with a negative targeted biopsy, a degree of reassurance is provided that is much greater than that offered by the older, blind biopsy method.
The new fusion biopsy method is described in this brief online video. Prostate cancer is the most frequently diagnosed cancer in men aside from skin cancer. An estimated 233,000 new cases of prostate cancer will occur in the United States in 2014. Among those men, nearly 30,000 will die.